Raney's Lightbulb-Lizard (Riama raneyi)

Reptiles of Ecuador | Sauria | Gymnophthalmidae | Riama | Riama raneyi

English common name: Raney's Lightbulb-Lizard.

Spanish common name: Lagartija minadora de Raney.

Recognition: ♂♂ 18.8 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=8.2 cm. ♀♀ 16.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=8 cm.. Lightbulb-lizards are easily distinguishable from other lizards by their fossorial (living underground) habits and extremities so short that the front and hind limbs cannot reach each other.^1,2 The Raney's Lightbulb-Lizard (Riama raneyi) is one of four species of Riama known to occur along the Amazonian slopes of the Andes in northeastern Ecuador. Riama raneyi differs from the other three species (R. anatoloros, R. orcesi, and R. simotera) by lacking dorsolateral stripes and by having only one superciliary scale.² Adult males differ from females by being larger, more colorful, and having broader heads.

Variation among individuals of Riama raneyi

Figure 1: Raney's Lightbulb-Lizards (Riama raneyi) from El Carmelo–Santa Bárbara road, Sucumbíos province, Ecuador. j=juvenile

Natural history: Locally commonRecorded weekly in densities above five individuals per locality.. Riama raneyi is a fossorial lizard that inhabits old-growth to heavily disturbed high evergreen montane forests. It also occurs in areas containing a mixture of pastures, crops, rural houses, and remnants of native vegetation.³ Raney's Lightbulb-Lizards spend most of their lives in tunnels they excavate in areas of soft soil, in dirt walls, or under rocks and logs.³ Individuals have also be seen moving at ground level during the day.³ Females lay clutches of 2–3 eggs in communal nesting sites such as under rocks.^2,3 As many as 8–24 eggs have been found in these sites, and females occasionally have been seen coiled around the eggs, presumably protecting them.^2,3

When dug up or otherwise exposed, individuals of Riama raneyi will quickly flee under cover. If captured, they may bite or readily shed the tail. Raney's Lightbulb-Lizards are susceptible to high temperatures, dying if exposed to the sun or even if handled for longer than just a few seconds.³ A Roadside Hawk (Rupornis magnirostris) was seen preying upon an individual of R. raneyi.⁴ Members of this species can be found living alongside individuals of R. orcesi in the valley of the Papallacta river.² Differences like lager body size, but comparatively shorter limbs in R. raneyi could be allowing the coexistence between the two species by influencing the use of different microhabitats.²

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Conservation: Least Concern Believed to be safe from extinction given current circumstances.. Riama raneyi is proposed to be assigned in this category, instead of Vulnerable,⁵ following IUCN criteria,⁶ because the species occurs in three major protected areas (Antisana Ecological Reserve, Cayambe Coca National Park, and Sumaco National Park) and it is distributed over an area which retains the majority (~91.7%) of its forest cover.⁷ Therefore, the species is here considered to be facing no major immediate extinction threats.

Distribution: Riama raneyi is endemic to an estimated ~4,313 km² area along the Amazonian slopes of the Andes of northern Ecuador. The species has not been recorded in southern Colombia, but it almost surely occurs there. Riama raneyi occurs at elevations between 2430 and 3027 m (Fig. 2).

Figure 2: Distribution of Riama raneyi in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Riama does not appear to be a reference to any feature of this group of lizards, but a matter of personal taste. John Edward Gray usually selected girl’s names to use on reptiles.^8–11 The specific epithet raneyi honors Richard Raney, of Lawrence, Kansas, in recognition of his generous support towards the research that led to the discovery of this lizard species.²

See it in the wild: Raney's Lightbulb-Lizard are recorded rarely unless they are actively searched for by digging in areas of soft soil or by turning over rocks and logs in suitable habitats. Around the town El Carmelo, near the Ecuador–Colombia border, lizards of this species can be found with ~20–40% certainty if the search is targeted and carried out for a period of at least four hours.

Acknowledgments: Special thanks to Amanda Quezada, Harry Turner, and Frank Pichardo for finding the specimens of Riama raneyi pictured in this account. Thanks to Frank Pichardo for providing natural history data of R. raneyi. Thanks to Amanda Quezada for the post-processing of images. This account was published with the support of Secretaría Nacional de Educación Superior Ciencia y Tecnología (programa INEDITA; project: Respuestas a la crisis de biodiversidad: la descripción de especies como herramienta de conservación; No 00110378), Programa de las Naciones Unidas (PNUD), and Universidad San Francisco de Quito (USFQ).

Authors: Alejandro Arteaga^aAffiliation: Khamai Foundation, Quito, Ecuador.

Photographer: Jose Vieira^aAffiliation: Tropical Herping (TH), Quito, Ecuador.^,^bAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2020) Raney's Lightbulb-Lizard (Riama raneyi). In: Arteaga A, Bustamante L, Vieira J, Guayasamin JM (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/YRFI9484

Literature cited:

Doan TM, Castoe TA (2005) Phylogenetic taxonomy of the Cercosaurini (Squamata: Gymnophthalmidae), with new genera for species of Neusticurus and Proctoporus. Zoological Journal of the Linnean Society 143: 405–416. DOI: 10.1111/j.1096-3642.2005.00145.x
Kizirian DA (1996) A review of Ecuadorian Proctoporus (Squamata: Gymnophthalmidae) with descriptions of nine new species. Herpetological Monographs 10: 85–155. DOI: 10.2307/1466981
Field notes, Reptiles of Ecuador book project.
Frank Pichardo, pers. comm.
Cisneros-Heredia DF, Valencia J, Almendáriz A, Brito J (2019) Riama raneyi. The IUCN red list of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2019-3.RLTS.T50950543A50950550.en
IUCN (2001) IUCN Red List categories and criteria: Version 3.1. IUCN Species Survival Commission, Gland and Cambridge, 30 pp.
MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
Gray JE (1831) Description of a new genus of ophisaurean animal, discovered by the late James Hunter in New Holland. Treuttel, Würtz & Co., London, 40 pp.
Gray JE (1831) A synopsis of the species of the class Reptilia. In: Griffith E, Pidgeon E (Eds) The animal kingdom arranged in conformity with its organization. Whittaker, Treacher, & Co., London, 1–110.
Gray JE (1838) Catalogue of the slender-tongued saurians, with descriptions of many new genera and species. Annals and Magazine of Natural History 1: 274–283.
Gray JE (1845) Catalogue of the specimens of lizards in the collection of the British Museum. Trustees of the British Museum, London, 289 pp.

Appendix 1: Locality data used to create the distribution map of Riama raneyi in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

Country	Province	Locality	Source
Ecuador	Carchi	5.7 km NW El Carmelo	Kizirian 1996
Ecuador	Carchi	6 km NW El Carmelo	This work
Ecuador	Carchi	El Carmelo	This work
Ecuador	Carchi	Julio Andrade–El Carmelo	This work
Ecuador	Napo	3 km E Cuyuja	Kizirian 1996
Ecuador	Napo	Above sendero Guacamayos	Kizirian 1996
Ecuador	Napo	Cuyuja	Kizirian 1996
Ecuador	Napo	Río Quijos norte	DHMECN 2910
Ecuador	Napo	Sumaco camp 2	This work
Ecuador	Sucumbíos	18 km E Santa Bárbara	Kizirian 1996
Ecuador	Sucumbíos	2 km E Santa Bárbara	Sánchez-Pacheco et al. 2012
Ecuador	Sucumbíos	32 km E Julio Andrade	This work
Ecuador	Sucumbíos	Near La Alegría	Kizirian 1996
Ecuador	Sucumbíos	Near Santa Bárbara	Sánchez-Pacheco et al. 2012
Ecuador	Sucumbíos	Santa Bárbara, near border	Field notes of Elicio Tapia